Re: [PATCH v3 20/35] x86/bugs: Define attack vectors

Josh Poimboeuf
2025-02-20T22:04:43Z

On Tue, Feb 18, 2025 at 09:52:03AM +0100, Borislav Petkov wrote:
> On Mon, Feb 17, 2025 at 11:05:01PM -0800, Josh Poimboeuf wrote:
> > IMO, make them generic from the start, then there's less churn and it's
> > easy to port the other arches.
> >
> > If we went with putting everything in "mitigations=", making them
> > generic would be the obvious way to go anyway.
>
> Just to make sure we're all on the same page: we obviously cannot enable
> and test and support a mitigaion on another arch like, say, arm64, or so.
>
> This needs to come from the respective arch maintainers themselves and they'll
> have to say, yes, pls, enable it and we'll support it. We should not go "oh,
> this would be a good idea to do on all arches" without hearing from them
> first, even if it is a good idea on its face.
>
> That's why those are x86-only as they should be initially.

I wasn't suggesting that this patch set should *enable* it on all
arches. Of course that would need to be reviewed by the respective arch
maintainers.

But looking ahead, this *will* be needed for the other arches, for the
same reason we have a generic mitigations=off. It's a user problem, not
an arch-specific one. Users need a simple interface that works
everywhere. That's why I suggested integrating it into "mitigations=".

--
Josh